Caltrans and their consultants have conducted two investigations at the bridge site. The first, completed in June 2014, termed a "bridge Survey,"
determined the concentration of wood preservative constituents in the structural members of the bridge for waste classification, the level of lead
present in the bridge rail paint system, and if asbestos containing materials were present. This "survey" investigation provided a group of
"constituents of concern" (COCs) used to direct the follow up investigation. The second investigation, termed a "preliminary Site Investigation" (PSI),
completed in December 2014, focused on determining if a release of any COCs had occurred in the immediate vicinity of the bridge. All investigations
to date have occurred within the 100-foot wide State Highway Right of Way at the bridge site.